1. Field of the Invention
This invention relates to a method of and apparatus for taping an article in which a preselected length of tape is severed from a tape supply prior to winding the preselected length of tape on the article.
2. Description of the Prior Art
It is standard practice in the manufacture of certain types of electrical coils formed by winding wires on a plastic bobbin, to wind a preselected length of protective electrically insulating adhesive tape about the windings of the coils. In automatic machines for this purpose, such as is disclosed in the U.S. Pat. No. 3,350,255 issued Oct. 31, 1967 to R. W. Twigg, a leading end portion of the adhesive tape is adhered to the outermost winding of the coil and the bobbin is rotated to wind a preselected length of the tape about the winding while pulling the tape from a tape supply. The tape then is cut between the portion of the tape wound on the coil and the tape supply, and the trailing end of the wound tape is pressed down onto the coil. Similar apparatus also is shown in the U.S. Pat. No. 3,314,452 to J. S. Cartwright et al. issued Apr. 18, 1967 and the U.S. Pat. No. 3,713,599 to N. F. Smith et al. issued Jan. 30, 1973. In apparatus of this type, to reduce the tension in the tape as it is pulled from the tape supply, the tape may be routed about a guide roller mounted on a spring loaded tension arm, as for example as disclosed in the U.S. Pat. No. 3,471,098, issued Oct. 7, 1969 to F. J. Jannett.
While prior known apparatus for the taping of electrical coils as above described have been satisfactory where the wire forming the windings of the coil is of relatively large diameter, such as less than 30 gauge (10 mils), difficulties are encountered in utilizing such machines in the taping of coils in which the wire of the coil windings is of smaller diameter. In this connection, the back tension on the tape as it is wound on the coil windings, even where a tension control arm is utilized, tends to break the fine wire in tension between the portions of each winding on the bobbin and its terminations on terminals of the bobbin. There also is a tendency for the tape, as it is pulled from the tape supply, to twist and/or otherwise become misaligned with the coil so that the tape adheres to and rides up on one of the flanges of the bobbin, whereby the tape is not properly wound on the coil in covering relationship. In addition, the twisted and/or misaligned tape also tends to break the wires of the windings on the bobbin in tension. Accordingly, this invention is intended to provide a method and apparatus which is particularly suited for the taping of electrical coils formed with small gauge wire without any significant tape back tension, twisting or misalignment.
The W. Hoffman U.S. Pat. No. 3,834,963, issued Sept. 10, 1974, is directed to the applying of labels to cylindrical containers or cans. In this patent the labels are fed in a continuous strip from a supply to a rotating vacuum feed drum and each label is severed from the supply as the leading end of the label reaches the feed drum. The feed drum then transfers the severed label to a position where the leading end portion of the label is attached to a respective one of the containers. Subsequently, the containers is rotated by engagement between a fixed surface and a traveling belt to wrap the label on the container. Similarly, the J. W. Toensing U.S. Pat. No. 3,159,325, issued Dec. 1, 1964, discloses a taping apparatus in which a tape is fed from a continuous supply and in which pieces of tape are successively cut from the supply and applied to respective articles. However, neither of the devices of these patents are suitable for applying tape to the windings of electrical coils.